Department of Orthopaedics, Institute of Clinical Sciences, the Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
Sahlgrenska University Hospital, Mölndal, Sweden.
Cartilage. 2021 Dec;13(2_suppl):1755S-1769S. doi: 10.1177/1947603520903788. Epub 2020 Feb 18.
Large cartilage defects and osteoarthritis (OA) cause cartilage loss and remain a therapeutic challenge. Three-dimensional (3D) bioprinting with autologous cells using a computer-aided design (CAD) model generated from 3D imaging has the potential to reconstruct patient-specific features that match an articular joint lesion.
To scan a human OA tibial plateau with a cartilage defect, retrieved after total knee arthroplasty, following clinical imaging techniques were used: (1) computed tomography (CT), (2) magnetic resonance imaging (MRI), and (3) a 3D scanner. From such a scan, a CAD file was obtained to generate G-code to control 3D bioprinting directly into the tibial plateau lesion.
Highest resolution was obtained using the 3D scanner (2.77 times more points/mm than CT), and of the 3 devices tested, only the 3D scanner was able to detect the actual OA defect area. Human chondrocytes included in 3D bioprinted constructs produced extracellular matrix and formed cartilage tissue fragments after 2 weeks of differentiation and high levels of a mature splice version of collagen type II (Col IIA type B), characteristic of native articular cartilage and aggrecan (ACAN). Chondrocytes had a mean viability of 81% in prints after day 5 of differentiation toward cartilage and similar viability was detected in control 3D pellet differentiation of chondrocytes (mean viability 72%).
Articular cartilage can be formed in 3D bioprints. Thus, this 3D bioprinting system with chondrocytes simulating a patient-specific 3D model provides an attractive strategy for future treatments of cartilage defects or early OA.
大的软骨缺损和骨关节炎（OA）导致软骨丢失，仍然是一个治疗挑战。使用源自 3D 成像的计算机辅助设计（CAD）模型的自体细胞 3D 生物打印具有重建与关节病变匹配的患者特定特征的潜力。
为了扫描经全膝关节置换术切除的人类 OA 胫骨平台软骨缺损，采用以下临床成像技术进行扫描：（1）计算机断层扫描（CT），（2）磁共振成像（MRI）和（3）3D 扫描仪。从这样的扫描中，获得 CAD 文件以生成 G 代码来直接控制 3D 生物打印到胫骨平台病变中。
使用 3D 扫描仪获得了最高分辨率（比 CT 多 2.77 倍的点/mm），在测试的 3 种设备中，只有 3D 扫描仪能够检测到实际的 OA 缺陷区域。包含在 3D 生物打印构建体中的人软骨细胞在分化后的 2 周内产生细胞外基质并形成软骨组织碎片，并且具有高比例的成熟拼接型 II 型胶原（Col IIA 型 B），这是天然关节软骨和聚集蛋白聚糖（ACAN）的特征。在向软骨分化的第 5 天，打印中的软骨细胞平均存活率为 81％，在对照 3D 软骨细胞球分化中检测到相似的存活率（平均存活率为 72％）。
可以在 3D 生物打印中形成关节软骨。因此，这种具有模拟患者特定 3D 模型的软骨细胞的 3D 生物打印系统为将来治疗软骨缺损或早期 OA 提供了有吸引力的策略。
